摘要：
BACKGROUND: The internal transcribed spacer 2 (ITS2) region of nuclear ribosomal DNA is regarded as one of the candidate DNA barcodes because it possesses a number of valuable characteristics, such as the availability of conserved regions for designing universal primers, the ease of its amplification, and sufficient variability to distinguish even closely related species. However, a general analysis of its ability to discriminate species in a comprehensive sample set is lacking. METHODOLOGY/PRINCIPAL FINDINGS: In the current study, 50,790 plant and 12,221 animal ITS2 sequences downloaded from GenBank were evaluated according to sequence length, GC content, intra- and inter-specific divergence, and efficiency of identification. The results show that the inter-specific divergence of congeneric species in plants and animals was greater than its corresponding intra-specific variations. The success rates for using the ITS2 region to identify dicotyledons, monocotyledons, gymnosperms, ferns, mosses, and animals were 76.1%, 74.2%, 67.1%, 88.1%, 77.4%, and 91.7% at the species level, respectively. The ITS2 region unveiled a different ability to identify closely related species within different families and genera. The secondary structure of the ITS2 region could provide useful information for species identification and could be considered as a molecular morphological characteristic. CONCLUSIONS/SIGNIFICANCE: As one of the most popular phylogenetic markers for eukaryota, we propose that the ITS2 locus should be used as a universal DNA barcode for identifying plant species and as a complementary locus for CO1 to identify animal species. We have also developed a web application to facilitate ITS2-based cross-kingdom species identification (http://its2-plantidit.dnsalias.org).

摘要：
This paper extends the work of Rang et al. (2009). We use a greater number of linear and nonlinear generalized autoregressive conditional heteroskedasticity (GARCH) class models to capture the volatility features of two crude oil markets - Brent and West Texas Intermediate (WTI). The one-, five- and twenty-day out-of-sample volatility forecasts of the GARCH-class models are evaluated using the superior predictive ability test and with more loss functions. Unlike Kang et al. (2009), we find that no model can outperform all of the other models for either the Brent or the WTI market across different loss functions. However, in general, the nonlinear GARCH-class models, which are capable of capturing long-memory and/or asymmetric volatility, exhibit greater forecasting accuracy than the linear ones, especially in volatility forecasting over longer time horizons, such as five or twenty days. (C) 2010 Elsevier B.V. All rights reserved.

摘要：
Logistic regression analysis is an effective approach to the classification problem. However, it may lead to high misclassification rate in real decision procedures. Decision-Theoretic Rough Sets (DTRS) employs a three-way decision to avoid most direct misclassification. We integrate logistic regression and DTRS to provide a new classification approach. On one hand, DTRS is utilized to systematically calculate the corresponding thresholds with Bayesian decision procedure. On the other hand, logistic regression is employed to compute the conditional probability of the three-way decision. The empirical studies of corporate failure prediction and high school program choices' prediction validate the rationality and effectiveness of the proposed approach. (C) 2013 Elsevier Inc. All rights reserved.

摘要：
Virtual Geographic Environments (VGEs) are proposed as a new generation of geographic analysis tool to contribute to human understanding of the geographic world and assist in solving geographic problems at a deeper level. The development of VGEs is focused on meeting the three scientific requirements of Geographic Information Science (GIScience) multi-dimensional visualization, dynamic phenomenon simulation, and public participation. To provide a clearer image that improves user understanding of VGEs and to contribute to future scientific development, this article reviews several aspects of VGEs. First, the evolutionary process from maps to previous GISystems and then to VGEs is illustrated, with a particular focus on the reasons VGEs were created. Then, extended from the conceptual framework and the components of a complete VGE, three use cases are identified that together encompass the current state of VGEs at different application levels: 1) a tool for geo-object-based multi-dimensional spatial analysis and multi-channel interaction, 2) a platform for geo-process-based simulation of dynamic geographic phenomena, and 3) a workspace for multi-participant-based collaborative geographic experiments. Based on the above analysis, the differences between VGEs and other similar platforms are discussed to draw their clear boundaries. Finally, a short summary of the limitations of current VGEs is given, and future directions are proposed to facilitate ongoing progress toward forming a comprehensive version of VGEs. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.

作者机构：
[Xu, David Jingjun] Sauder School of Business, University of British Columbia, Canada;[Liao, Stephen Shaoyi] School of Economics and Management, South West JiaoTong University, China;[Liao, Stephen Shaoyi] Department of Information Systems, City University of Hong Kong, Hong Kong;[Li, Qiudan] Laboratory of Complex Systems and Intelligence Science, Institute of Automation, Chinese Academy of Sciences, China

摘要：
In this study, a laboratory seismoelectric measurement for the permafrost model with a frozen-unfrozen interface is presented. The measurements obtained experimentally confirms that an electric double-layer can be formed at the interface due to the electric and mechanical differences of the frozen and unfrozen media, and seismoelectric conversion EM waves originted from the relative motion of the charges in the electric double-layer can be observed at n x 10 kHz frequency band. This suggests a potential application for non-destructive detection of the frost depth. Citation: Liu, Z., L. Yuan, X. Zhang, Z. Liu, and H. Wu (2008), A laboratory seismoelectric measurement for the permafrost model with a frozen-unfrozen interface, Geophys. Res. Lett., 35, L21404, doi: 10.1029/2008GL035724.

摘要：
This paper provides an approach in the context of green supply chain management, using game theory to analyze the strategies selected by manufacturers to reduce life cycle environmental risk of materials and carbon emissions. Through the application of the 'tolerability of risk' concept, a basis for determining the extent of environmental risk and carbon emissions reduction has been established. Currently, scant attention is given to holistic supervision of the supply chain with respect to carbon emissions by governments, and thus the starting hypothesis here is that the default strategy that manufacturers will adopt is only to reduce carbon emissions, and thereby environmental risk, in so far as this is compatible with the aim of increasing revenue. Moreover, we further hypothesize that, once necessary governmental policy has been established in the supply chain management, the strategic choices of the manufacturers would be influenced by government penalties or incentives. A case example is provided to demonstrate the insight that indicates the application of game theory. The limitations of the game model and analysis are discussed, laying a foundation for further work. (C) 2012 Elsevier Ltd. All rights reserved.

作者机构：
[Yuan, Hongping] School of Economics and Management, Southwest Jiaotong University, Chengdu, China;[Shen, Liyin] Department of Building and Real Estate, The Hong Kong Polytechnic University, Hong Kong;[Lu, Yujie] Department of Civil and Environmental Engineering, University of Maryland, MD, United States;[Lu, Yujie] School of Economics and Management, Tongji University, Shanghai 200092, China;[Chini, Abdol R.] Rinker School of Building Construction, University of Florida, FL, United States

摘要：
In this paper, we apply time-varying copulas to investigate whether a contagion effect existed between energy and stock markets during the recent financial crisis. Using the WTI oil spot price, the S&P500 index, the Shanghai stock market composite index and the Shenzhen stock market component index returns, evidence was found for a significantly increasing dependence between crude oil and stock markets after the failure of Lehman Brothers, thus supporting the existence of contagion in the sense of Forbes and Rigobon's (2002) definition. Moreover, increased tail dependence and symmetry characterize all the paired markets. This indicates that significant increases in tail dependence are an actual dimension of the contagion phenomenon and that crude oil and stock prices are linked to the same degree regardless of whether markets are booming or crashing during the sample period. Finally, the contagion effect is found to be much weaker for China than the US. The empirical results have potentially important implications for risk management. (C) 2012 Elsevier B.V. All rights reserved.

摘要：
We demonstrate the efficiency and effectiveness of a tradable credit system in managing the morning commute congestion with identical and nonidentical commuters. The credit system consists of a time-varying credit charged at the bottleneck and an initial credit distribution to the commuters, where the credits are universal in terms of time. Credits are tradable between the commuters and the credit price is determined by a competitive market. Under the assumption that late-arrival is not allowed, we prove that an optimal credit charging scheme, which completely eliminates the bottleneck queue, always exists despite how commuters vary in their value-of-time (VOT). The optimal charge rate is strictly increasing and convex with time, which therefore drives the commuters to depart in the increasing order of their VOT. The optimal credit charging scheme is pareto-improving, but may cause undesirable welfare distribution among the commuters. Our study shows that a combination of an initial credit distribution and an optimal credit charging scheme can simultaneously achieve system optimum and certain forms of equality (e.g., "numerical" or "proportional" equality), and that the commuters in the middle VOT bracket will receive the most credits under the proportionally equitable credit distribution. (C) 2013 Elsevier Ltd. All rights reserved.